Module org.eclipse.jetty.util

Package org.eclipse.jetty.util

Interface Attributes

All Known Subinterfaces:

Environment

All Known Implementing Classes:

AttributeContainerMap, Attributes.Layer, Attributes.Lazy, Attributes.Mapped, Attributes.Synthetic, Attributes.Wrapper, AttributesMap

public interface Attributes

Attributes. Interface commonly used for storing attributes.

Some attributes may be "hidden" attributes, in that they are only found by an explicit call to getAttribute(String) and they do not otherwise appear in getAttributeNameSet() or asAttributeMap().

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static class	Attributes.Layer	An Attributes implementation backed by another Attributes instance, which is treated as immutable, but with a ConcurrentHashMap used as a mutable layer over it.
static class	Attributes.Lazy	An Attributes implementation that lazily creates a backing map iff it is actually needed.
static class	Attributes.Mapped	An Attributes implementation backed by a ConcurrentHashMap.
static class	Attributes.Synthetic	An abstract implementation of Attributes.Wrapper that provides a mechanism for synthetic attributes that can be modified or deleted.
static class	Attributes.Wrapper	A Wrapper of attributes

Field Summary

Fields

Modifier and Type	Field	Description
static final Attributes	NULL

Method Summary

Modifier and Type	Method	Description
default Map<String,Object>	asAttributeMap()
default void	clearAttributes()	Clear all attribute names
boolean	equals(Object o)
static boolean	equals(Attributes attributes, Object o)
Object	getAttribute(String name)	Get an attribute by name.
Set<String>	getAttributeNameSet()	Get the immutable set of attribute names.
int	hashCode()
static int	hashCode(Attributes attributes)
Object	removeAttribute(String name)	Remove an attribute
Object	setAttribute(String name, Object attribute)	Set an attribute
static Attributes	unwrap(Attributes attributes)	Unwrap all Attributes.Wrappers of the attributes
static <T extends Attributes.Wrapper> T	unwrap(Attributes attributes, Class<T> target)	Unwrap attributes to a specific attribute Attributes.Wrapper.

Field Details

NULL

static final Attributes NULL

Method Details

removeAttribute

Object removeAttribute(String name)

Remove an attribute

Parameters:

name - the attribute to remove

Returns:

the value of the attribute if removed, else null

setAttribute

Object setAttribute(String name,
 Object attribute)

Set an attribute

Parameters:

name - the attribute to set

attribute - the value to set. A null value is equivalent to removing the attribute.

Returns:

the previous value of the attribute if set, else null

getAttribute

Object getAttribute(String name)

Get an attribute by name. Some attributes may be "hidden" attributes, in that they are only found by an explicit call to getAttribute(String) and they do not otherwise appear in getAttributeNameSet() or asAttributeMap().

Parameters:

name - the attribute to get

Returns:

the value of the attribute, or null if no such attribute exists

getAttributeNameSet

Set<String> getAttributeNameSet()

Get the immutable set of attribute names.

Returns:

Set of attribute names, or an empty set if there are no attributes.

asAttributeMap

default Map<String,Object> asAttributeMap()

clearAttributes

default void clearAttributes()

Clear all attribute names

hashCode

int hashCode()

Overrides:

hashCode in class Object

equals

boolean equals(Object o)

Overrides:

equals in class Object

unwrap

static Attributes unwrap(Attributes attributes)

Unwrap all Attributes.Wrappers of the attributes

Parameters:

attributes - The attributes to unwrap, which may be a Attributes.Wrapper.

Returns:

The core attributes

hashCode

static int hashCode(Attributes attributes)

equals

static boolean equals(Attributes attributes,
 Object o)

unwrap

static <T extends Attributes.Wrapper> T unwrap(Attributes attributes,
 Class<T> target)

Unwrap attributes to a specific attribute Attributes.Wrapper.

Type Parameters:

T - The type of the target Attributes.Wrapper.

Parameters:

attributes - The attributes to unwrap, which may be a Attributes.Wrapper

target - The target Attributes.Wrapper class.

Returns:

The outermost Attributes.Wrapper of the matching type of null if not found.